Grinder



s. F. OSSING 2,141,664

v GRINDER Filed Dec. 28, 1936 2 Sheets-shed: 1

//v VE/VTOE. STANLEY FOssmcs,

BY Mm,

Patented Dec. 27, 1938 UNITED STATES GRINDER Stanley F. Ossing, Columbus, Ohio, assignor to The Jeiirey Manufacturing Company, a corporation of Ohio Application December 28, 1936, Serial Rim-117,845 1 Claim. (@l. 83-11) This invention relates to a grinder or shredder,

and particularly. to such a device which is adapted to grind sewage and to reduce particularly the fibrous material into short fibers.

An ,object of the invention is to provide a grinder of the above class which will very effectively reduce sewage and particularly fibrous 1 material so the fibrous material will be readily washed from the grinder and will readily pass through'sewage disposal apparatus, particularly the pumps of said apparatus.

Another object of the invention is to provide an improved form of swing hammer in a grinder of the above class.

Still another object of the invention is to provide an improved grating which will act to allow reduced material to pass from the grinding chamber in a progressive manner.

A further object is to provide a grinder mechanism to reduce fibrous materials in a green garbage mixture to a pulp so finely divided that the pulped garbage is rendered suitable for discharge into a sewage treatment plant. A

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

In the accompanying drawings, Fig. l is a side elevational view of the grinder comprising my invention;

Fig. 2 is a transverse elevation'al sectional viewtaken on the line 22 of Fig. 1 looking in the direction of the arrowsi Fig. 3 is a sectional elevational view taken on the line 3-3 of Fig. 2 looking in the direction of the arrows;

Fig. 4 is a perspective view of one of the grating bars employed in my improved grinder;

Fig. 5 is a modified form of grating bar; and Fig. 6 is an enlarged perspective view of a swing hammer comprising my invention.

In the development of sewage disposal apparatus, as well as the development of garbage disposal apparatus, the practice has been introduced of grinding sewage screenings and of grinding garbage and introducing it into' the sewage 5 stream to be treated by sewage disposal apparatus. It has been found that there is an appreciable amount of fibrous material in sewage screenings. A certain amount of fibrous material has also been encountered in garbage. The

50 reduction of the sewage screenings and/or garbage, particularly due to the presence of the fibrous material, which may be in the forms of rags or cloth, has presented a serious problem because saidfibrous material tends to clog the 55 grinder and if it is passed through the grinder it tends to clog the mechanism of the sewage disposal apparatus, particularly the pumps.

The grinder herein disclosed is designed par-' ticularly to reduce sewage screenings or garbage, or both, and more particularly to reduce the 5 fibrous material to relatively short threads whereby it will not clog the grinder but will pass readily through the grating thereof and will not clog any subsequent apparatus of the sewage disposal system. 10

As seen in Figs. 1, 2 and 3 of the drawings, said grinder comprises a casing l0 formed by a bottom casting II and a top member l2. The top member I2 is provided with an integral hopper i3 and is pivotally attached to the casting II at its rear l5 end by a hinge M and a bracket 15. At its forward end the top member I2 is bolted to the casting II by bolts, one of which is seen at it. It 'mayalso be mentioned that the bracket i5 is atta ed to the casting H by bolts, one of which 2 is seen at Hi. This hinged connection of the top member i2 provides for its swinging thereby providing access to the interior of the casing 90. The top member I2 is provided with a plurality of removable and renewable liners comprising 25 rear liner i1, flat side liners l8, l8, and front liner I9. Said liners l1, l8 and I9 are removably attached by appropriate nuts and bolts seen at I20. Liners l8, l8 terminate at the bottom of top member l2. 30

(Jo-operating with the liners i1, I8 and I9 of I the top member i2 is a grating 20 carried by the bottom casting II, to provide a reducing chamher 2!.

As will be hereinafter explained in full detail, 35 the grating 20 has the double function of providing a screen for properly reduced'material and of cooperating with the rotor to reduce the material to'a desirable fine state.

The grating 20 is formed by a plurality of 40 transversely extending grating bars 22, the notched ends 23 of which are supported by a pair of arcuate supporting bars 24, 24, best seen in Fig. 2, which bars 24, 24 rest upon arcuate flanges in the casting II and are provided with tapering notches to receive the tapering side walls of the grating bars 22. Each of the supporting bars, 24 is preferably formed in a plurality of segments, asbest seen in Fig. 3 .of the drawings, to facilitate its removal. I

To hold the grating bars 22 in place and also to provide a wearing liner for the lower portion.

' of the reducing chamber 2|, I provide on each side of the casting II a renewable and removable liner 25 which is attachedto said casting II by 58 appropriate nuts and bolts 25. The outer periphery of said liner 25 rests upon the tops of the transversely extending grating bars 22 thereby holding them in their proper places.

To provide access to the lower portion of the reducing chamber 2| above the grating 20 I provide removable plugs 21, removably held in place by screws I21, the bottoms of which plugs rest upon a few of the bars 22 adjacent the bottom of the grating 20 atwhich the liner 25 is severed. At this position it will be evident that the grating bars 22 will be held down by the plugs 21 rather than by said liner 25.

To provide access to the lower surface of the grating 20 I provide a removable door 28 adjacent the front of said casting H, as shown in Fig. 3.

To hold the supporting bars 24, 24 rigidly in place I provide at each end thereof a transversely extending bar, the bar at the front end being designated 29 and'the bar at the rear end being designated 38. As clearly seen in Fig. 1 of the drawings, the bars 29 and 33 may be slid through one side of the casing l9 and covered by removable cover plates3l and 32, respectively. Said bars 29 and 38 are, in turn, held down by the top member l2 and the bracket l which rest on the tops of them. Furthermore, the top member l2 and bracket l5 have inward projections forming overhanging abutments under which the bars 29, 30 extend. Appropriate spacers 33 and 34 are preferably provided behind the bars 29 and 30. It is also to be noted that said bars 20 and 30 have a corner forming an acute angle which provides a cutting edge to cooperate with the rotor structure to aid the reduction of the material, as hereinafter described in more detail.

Extending transversely across the top of the reduction chamber 2i and carried by the top member I2 is a square bar 35 held in place by the square notches l8 in the side plates of member I2 and kept. from moving endwise by removable cover plates 36, 35. This bar 35 cooperates with the rotor to prevent material ,from being thown out of reduction chamber 2| and also cooperates therewith to aid in the reduction of any material which reaches said bar 35 without being properly reduced. The elongated straight cutting edges 29 and 30' serve to assist in reduction and keep the smaller particles in the lower chamber 2|.

Attention is now directed particularly to Figs. 3 and 4 and to the construction of the grating bars 22. Each of said grating bars 22 is preferably wedge-shaped, thereby to provide the minimum of clearance adjacent their top edges 31 and 38, (Fig. 4), to the end that any material which passes beyond said top edges will be free to pass entirely through said grating without clogging.

- The top edges 31 and 38 of each of the bars 22 provides a cutting edge.

As is clearly illustrated in Fig. 3 of the drawings, the spacing between the top edge 38 of each of the parallel grating bars 22 and the top edge 38 of the next adjacent grating bar 22, is progressively increased in the direction of rotation of the rotor designated by the arrow 39. This is provided to the end that there will be a progressive grading of the material which may pass through said grating 20. v

In order to increase the cutting edges of each of the grating bars 22 said bars are provided with a top groove 40 which is preferably V-shaped and has its edges spaced from the edges 31.and 38. In a modified form. of grating bar 22', seen in Fig. 5, a groove 43' provides a leading or receiving knife shearing and shredding edge 31' and a trailing or ejecting flat shearing and crushing edge 38'. In practice the grating 20 may be formed of bars 22 or 22' or a combination of said bars, but in any arrangement the teeth 56 have shearing edges which cooperate with the shearing edges 31, 38 or 31', 38', to shred the material.

Mounted upon a pair of end brackets 4|, 4| formed integral with the casting II is a pair of anti-friction bearing boxes 42, 42 which support a transversely extending shaft 43 provided with a drive pulley 44. The shaft 43 will be held against axial movement by lock nuts 45, 45 which cooperate with the bearing boxes 42, 42. A grease cup 46 is also preferably provided for each of the anti-friction bearings carried by the boxes 42, 42.

Mounted upon the shaft 43 for rotation within the reducing chamber 2!! is a rotor 47 which cooperates with the grating 20 and with the bars 29, 30 and 35 to effect a thorough reduction of material, particularly sewage screenings or garbage containing fibrous material. This reduction is effected principally by a high attrition action as it has been found in practice that it is very difficult to reduce fibrous material by a hammer action or by a cutting action alone. That is, while cutting takes place at the leading shearing edge 3? or 31', the material is moved by centrifugal force into the groove 40 or 40'.

Said rotor 41 is formed by a plurality of discs 48 which are keyed to the shaft 43 and spaced apart by keyed spacer. rings 49. The rotor 41 also includes flanged end discs 50, 50, one adjacent each end, which are also keyed to the shaft 43, and which are held in intimate contact with an adjacent spacer ring 49 by end spacer rings 5|, 5|, the outer ends of which abut against appropriate bearings carried by bearing boxes 42, 42.

Extending transversely between the end discs 58, 50 and'held in place by appropriate cotter pins is a plurality of pivot rods 52. Upon said pivot rods 52 are pivoted swing hammers 53. Said swing hammers 53 are held in their proper positions by spacer rings 54, one side of which abuts a disc 48 or 50, and the other side of which abuts a swing hammer 53. 4

As seen in Fig. 3 of the drawings, there are eight of said pivot rods 52. Alternate circumferential hammers 53' are spaced upon opposite sides of a disc 48. This, of course, provides for said alternate hammers 53 to rotate in different planes thereby insuring a complete absence of with a hole 55 to pivot the hammer about a rod 52. The lower edge of the hammer 53 is provided with a plurality of teeth 55.

It is to be particularly noted that the leading face 5'! of each of the teeth 56 lies in a plane which passes through the axis of the hole 55. In other words, the face 5'! liesin a radial plane with respect to the axis of hole 55. In addition,

the tip of each tooth 56 is the same distance from the axis of hole 55. As a consequence, in

the swinging of any hammer 53 about a rod 52,

the distance of any of the teeth 5Gfrom the opposed grating bar 22 will not be less than a predetermined desired minimum. In practice amines :3;

it is preferred that this minimum clearance between a tooth 56 and the grating bars 22 be approximately one-eighth to three-sixteenths of an inch.

In the operation of the device comprising my invention, material to be reduced, such'as sewage screening or garbage is fed into the reduction chamber 2! by way of the hopper I3. The rotor M will be rotated in the direction of the arrow 39. The swing hammers 53, particularly by virtue of the plurality of the teeth 56, will cooperate with the grid bars 22 and with the bars 29, 3B and 35 to effect a thorough reduction of the material. The combination of the hammers 53 with the plurality of teeth 56 and the particular grid bars 22, which have not only the cutting edges 3?, 38, but also the grooves 40 which provide additional cutting edges, is particularly efficient to reduce fibrous material, principally by an attrition action, into relatively short strands or strings.

Due to the particular spacing of the grid bars 22 which increases progressively from one end to the other in the direction of rotation of the rotor ti as indicated by the arrow 39, there is a selective or grading action in the discharge of the reduced material through said grating 20, the finer particles being more readily discharged adjacent the forward portion of the grinding area and the larger particles being discharged adjacent the rear portion thereof.

It will be evident that the material will be retained in the reducing chamber 2! until it is sufficiently reduced to pass through the grating 20. It may also be noted that should any material tend to lodge in the upper part of the reducing chamber M, the hammer 53 in cooperation with the bar 35, will be efiective to reduce it.

It is thus evident that a grinder has been provided which is particularly adapted to reduce sewage screenings or garbage and is effective to reduce the fibrous material thereof into relatively short fibers which will readily clear the grinder and not choke or clog it, and which can be readily handled by apparatus of sewage disposal plants, including particularly the pumps, without choking'or clogging said pumps.

Obviously those skilled in the art may make various changes in the details and arrangement .of parts without. departing from the spirit and scope of the invention as defined by the claims hereto appended, and I therefore wish not to .be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of my invention, what I desire to secure by Letters Patent of the United States is:

In a grinder, the combination with a split casing formed by complementary top and bottom sections. of a rotor in said casing, a grating forming the bottom of a reducing chamber and comprising axially extending bars which are spaced apart progressively increasing amounts, removable bars carried by said bottom section and resting on opposite ends of said grating to hold it in place, means on said top section having bearing contact with said bars, and means for removably clamping said top and bottom sec tions together, thereby clamping said bars in grid holding position.

army r. ossmo. 

